Ultra-high Molecular Weight Polyethylene Fibers Research Articles

Experimental and numerical study of steel wire mesh reinforced G-HPC slab protected by UHMWPE FRC under multiple blast loadings

Engineering structures may experience multiple blast loadings owing to accidental explosions and terrorist attacks, however, few studies focused on the multiple blast loading effect on the structures. In this study, the multiple blast resistance of the steel wire mesh (SWM) reinforced geopolymer based high performance concrete (G-HPC) slabs protected by ultra-high molecular weight polyethylene (UHMWPE) fiber reinforced cloth (FRC) were investigated by experimental and numerical studies. The effects of the thickness and location of UHMWPE FRC on the multiple blast behavior of the SWM reinforced G-HPC slab were examined by parametric analysis. The failure modes and the blast-resistantmechanism of the slabs were revealed. The experimental results indicated that the SWM reinforced G-HPC slab exhibited superior resistance against multiple blast loadings as compared to the plain G-HPC slab. The SWM reinforced G-HPC slab protected by UHMWPE FRC has better multiple blast resistance, and the UHMWPE FRC effectively mitigated the blast loading and further reduced the damage to the slab. In addition, the findings of the parametric analysis revealed that UHMWPE FRC was more effective to enhance the blast resistance of a slab as it was placed on the bottom surface.

Preparation of ultra-high molecular weight polyethylene (UHMWPE) fiber copper(II) ions adsorbent by radiation grafting

Preparation of ultra-high molecular weight polyethylene (UHMWPE) fiber copper(II) ions adsorbent by radiation grafting

Value Coefficient of Polyethylene Fiber Soil Embankment Slope Based on Response Surface Analysis.

The utilization of polymers can strengthen soil, but at a high price. In this study, value coefficients were proposed to evaluate the cost-effectiveness of fiber-reinforced roadbeds, and the effects of embankment-slope-influencing factors on the value coefficients were analyzed by response surface methodology. Ultrahigh-molecular-weight polyethylene fiber (UPEF) was used as the reinforcement material for soil. First, the shear strength parameters of fiber soil with different fiber diameters were obtained from the direct shear tests to set the parameters of the finite element models. Second, three factors, namely filling height, slope angle, and fiber diameter, were selected as input parameters based on the Box–Behnken Design (BBD) experimental design method, and their effects on the value coefficient of the fiber soil embankment slope were investigated. Finally, the design parameters at the maximum value coefficient of the fiber soil embankment slope were determined based on the results of the response surface analysis. The results indicated that the addition of UPEF could effectively improve the cohesion of the soil; the interaction between the filling height and fiber diameter is most obvious. The optimization of design parameters based on the value coefficient of the fiber soil slope is a slope-engineering design method considering comprehensive benefits.

Dynamic response of UHMWPE plates under combined shock and fragment loading

Ultra-high molecular weight polyethylene (UHMWPE) fiber composite has been extensively used to construct lightweight protective structures against ballistic impacts, yet little is known about its performance when subjected to combined blast and fragment impacts. Built upon a recently developed laboratory-scale experimental technique to generate simulated combined loading through the impact of a fragment-foam composite projectile launched from a light gas gun, the dynamic responses of fully-clamped UHMWPE plates subjected to combined loading were characterized experimentally, with corresponding deformation and failure modes compared with those measured with simulated blast loading alone. Subsequently, to explore the underlying physical mechanisms, three-dimensional (3D) numerical simulations with the method of finite elements (FE) were systematically carried out. Numerical predictions compared favorably well with experimental measurements, thus validating the feasibility of the established FE model. Relative to the case of blast loading alone, combined blast and fragment loading led to larger maximum deflections of clamped UHMWPE plates. The position of the FSP in the foam sabot affected significantly the performance of a UHMWPE target, either enhancing or decreasing its ballistic resistance. When the blast loading and fragment impact arrived simultaneously at the target, its ballistic resistance was superior to that achieved when subjected to fragment impact alone, and benefited from the accelerated movement of the target due to simultaneous blast loading.

Fluid-structure interaction simulation and evaluation of ballistic impact of STF impregnated UHMWPE fiber composites

This study reveals the fluid-structure interaction simulation of the ballistic impact of shear thickening fluid (STF) impregnated with ultra-high molecular weight polyethylene (UHMWPE) fiber composites. The STF/UHMWPE composites pull-out test results are fitted to obtain a similar STF rheological curve. The STF/UHMWPE composites fluid-structure interaction (FSI) model was established to reproduce the local failure and stress distribution at each stage of the ballistic impact process. The comparison of the finite element analysis (FEA) and the experimental results showed that the fitting degree of the STF/UHMWPE composites to the impact energy absorption was 94.74%. STF treatment has dual effects on the impact resistance of fabrics, increasing the friction and enhancing the thickening effect.

Study on catechol/tetraethylenepentamine and nano zinc oxide co‐modifying ultrahigh molecular weight polyethylene fiber surface to improve interfacial adhesion

AbstractTo improve interfacial adhesion to rubber matrix, a lower cost surface modification strategy of ultrahigh molecular weight polyethylene (UHMWPE) fiber was proposed by replacing expensive dopamine with the two‐component system of catechol/tetraethylenepentamine (CAT/TEPA) and then depositing nano zinc oxide (ZnO NPs). By Michael addition reaction or Schiff base reaction between CAT and TEPA, the CAT/TEPA layer was coated on the fiber surface, and further served as a secondary functional platform to realize ZnO NPs deposition through coordination. The surface morphology, chemical structure and composition, wettability and thermal property of the UHMWPE fibers were investigated to evaluate the process and effect of the surface modification. The results of the single‐filament tensile test indicated that the tensile strength of the UHMWPE fibers has no deterioration after the modification treatment. In comparison with the original fiber, the pull‐out test showed that the highest interface adhesion between the modified UHMWPE fibers and rubber matrix increased by 80.4%. Additionally, it was found that the appropriate zinc ion concentration played an important role in the modification effect.

Study on the Aging Behavior of an Ultra-High Molecular Weight Polyethylene Fiber Barrier Net in a Marine Environment

In the present work, the performance of ultra-high molecular weight polyethylene (UHMWPE) barrier nets in marine environments is investigated by Fourier transform infrared spectroscopy, thermogravimetry, scanning electron microscopy, and tensile experiments. The chemical, morphological, thermal stability, and strength changes after aging in salt spray, hygrothermal, and ultraviolet (UV) environments are characterized. An environmental spectrum is designed to simulate a real service environment and predict the service life of UHMWPE. The results show that UV energy can activate UHMWPE molecules and lead to chain breaking, which lowers the breaking strength more efficiently than salt spray. In a hygrothermal environment, the UHMPE fibers bond into clumps, which causes a slight increase in breaking strength after the initial rapid decrease with aging time. The acceleration ratio of the environmental spectrum increases with increasing aging time, which may be caused by the cross-linking and degradation of macromolecular chains in the material. The environmental spectrum given by this work can be used to evaluate performance and predict the service life of UHMWPE barrier nets in marine environments.

Ballistic penetration damages of hybrid plain-woven laminates with carbon, Kevlar and UHMWPE fibers in different stacking sequences

Hybrid composite materials combine different fibers in preform and take advantages of different mechanical behaviors for improving ballistic impact damage tolerances. Here we report ballistic impact damages of plain-woven laminates with different hybrids and stacking sequences. Three kinds of hybrid laminates, i.e., carbon/Kevlar, carbon/ultra-high molecular weight polyethylene (UHMWPE), and UHMWPE/Kevlar, had been prepared and tested in ballistic penetration with fragment simulating projectiles (FSP). The residual velocities of the projectiles and impact damage morphologies of the laminates have been obtained to show impact energy absorptions for the different hybrid schemes. A microstructural model of the hybrid laminates had also been established to show impact damage mechanisms with finite element analysis (FEA). We found that the UHMWPE/Kevlar hybrid laminates with Kevlar layers as the front face have the highest energy absorption capacity, followed by the carbon/Kevlar hybrid laminates with carbon layers as the front face. The main damage modes are fiber breakages, matrix crack and interlayer delamination. The ballistic damage evolutions from the FEA results show that the major damage is shear failure for front layers, while tension failure for the back layers. We expect that the ballistic impact performance could be improved from the different hybrid schemes.

Ballistic response of ultra-high molecular weight polyethylene laminate impacted by mild steel core projectiles

This paper presents the effect of interlaminar shear property on the ballistic response of ultra-high molecular weight polyethylene (UHMWPE) fiber composite laminate and discusses the detailed progressive ballistic damage process. Specifically, two kinds of UHMWPE fiber composite laminates with different interlaminar shear strength (ILSS) are impacted by a standard projectile (7.62 mm × 39 mm), and their multi-scale internal damage morphologies are characterized. Based on damage patterns, an evaluation model of laminate energy absorption is established to analyze the dissipation mechanism of the kinetic energy of the projectile. Results of ballistic tests indicate that the reduction of ILSS may result in the degradation of anti-penetration performance and in more serious internal damage. Internal damage morphologies show that shear fracture and delamination fracture are the primary failure modes during ballistic impact. The energy absorption by the laminate via tensile deformation, delamination failure and shear failure may account for 56.21%, 17.45%, and 16.49% of the projectile kinetic energy, respectively. Hence, tensile deformation may be the primary energy dissipation mechanism of projectile kinetic energy.

Orientation evaluation of ultra-high molecular weight polyethylene fibers: previous studies and an improved method

Determination of the orientation of microfibrils within ultra-high molecular weight polyethylene (UHMWPE) fibers is considered to be an important method in evaluating the mechanical properties of the fibers. Four commonly used orientation evaluation methods are summarized and used to evaluate UHMWPE fibers at different drawing stages in the industrial line, and the results exhibit certain limitations. To overcome these limitations, a new evaluation method for quantitive characterization of UHMWPE fiber properties is proposed. Meanwhile, in situ small-angle X-ray scattering data of an UHMWPE fiber drawn at 100°C were used to perform a Pearson correlation coefficient test, and the results show a very strong correlation between the strain ratio and the evaluated coefficient.

Broadband stealth composite metastructure with high penetration protection

Microwave absorption plays an important role in modern electromagnetic protection and compatibility. However, lack of mechanical and impact design restricts their practical applications. Herein, a composite armor (CA) incorporating metastructure design with mixed characteristic periods was optimized by embedded genetic algorithms and inversion framework of equivalent impedance derivation. The −10 dB absorption bandwidth was covered from 2 GHz to 18 GHz. The impact-penetration ballistic experiments and simulation verified the penetration protection of CA against large caliber armor-piercing incendiary (API) with target impact speed of more than 745.1 m/s. The CA fabricated by ultra-high molecular weight polyethylene fiber reinforced polymer (UFRP), carbon fiber reinforced polymer (CFRP) and alumina ceramics showed better penetration protection performance than the counterparts with titanium and aluminum alloys with the same weight. Compared with traditional armor steel with similar protection performance, more than 30% weight is reduced for the proposed composite armor.

Self-heating effect on ultra-high molecular weight polyethylene fibres and composites

This paper investigates the self-heating effect observed during testing ultra-high molecular weight polyethylene (UHMWPE) fibres and their composites, in particular Dyneema® SK76 fibres and Dyneema® HB26 laminates. Monotonic and cyclic tests were carried out at strain rates between 0.00833 s−1 and 250 s−1, frequencies up to 20 Hz, and different mean stress, amplitude stress and stress ratios to evaluate the self-heating effect developing in the materials. Measurements of the specimen’s temperature were carried out using a thermochromic liquid crystal paint and an infrared sensor. Experimental results showed that the temperature increased during fibre testing by as much as 13.2 ± 0.2 °C and, even though the maximum temperature was below the melting temperature of the material, melting was observed. Tension-tension cyclic tests showed that the fatigue life of the coupon specimens significantly depended on the testing conditions. In some cases, the measured temperature was as high as 102 ± 1 °C. Depending on the fatigue parameters, the laminates showed two different types of failure modes: mechanical or thermal. Hence, it is important to take into account self-heating effects when designing engineering parts reinforced with UHMWPE fibres.

Experimental investigation on ballistics resistance of UHMWPE fiber laminates

To study the application of ultra-high molecular weight polyethylene fiber (UHMWPE) laminates in light protection field, the ballistic test was used to study the ballistic resistance of UHMWPE fiber materials. In the experiment, 9mm standard bullets were launched by a revolver pistol and 92 type pistol to penetrate the fiber laminates respectively, and the initial velocity of the bullet was recorded by the infrared tachometer. The influence of the areal density, the number of layers, the incident angle and the initial velocity on the protective properties of the fiber laminates were discussed, meanwhile, the microscopic characteristics of the failure mode of the fiber laminates were studied by stereomicroscope. The results show that the areal density and the layer number have obvious influence on the ballistic resistance of the fiber laminates, and the influence of the two materials should be taken into account. In the non-penetrating condition, the total deformation of the fiber laminates is large and the failure of the fiber bundle is the main failure mode. And when penetrated completely, the tensile fracture of fiber laminate material is the main failure mechanism. The study of this paper provides experimental reference for the structural design of UHMWPE fiber laminates.

Ballistic helmets: Recent advances in materials, protection mechanisms, performance, and head injury mitigation

Combat helmets provide protection against ballistic threats and blunt impact forces, and wearing them has greatly reduced head injuries and saved lives of many soldiers. With the new challenges from improvised explosive devices and urban combat operations in modern asymmetric military conflicts, future combat helmets are required to be highly protective, lightweight, comfortable to wear, and compatible with communication and other systems. The aim of this paper is to provide a comprehensive review of existing combat helmets based on aramid and UHMWPE fibers by addressing the critical issues including materials, ballistic impact mechanisms, design, manufacturing, performance, and head injury protection. Various ballistic fabrics and composites used for combat helmets are discussed. The ballistic impact mechanisms and mechanical responses of helmet composites are examined in view of experimental methods, analytical models, and numerical simulations. The strategies for helmet designs, including head coverage and curvature of helmet shell, manufacturing processes, and liner foam pads, are outlined. The performance of combat helmets as evaluated by ballistic testing and finite element simulations is summarized. Finally, the ballistic and blast impact induced head injuries are elaborated, and the possibility of behind armor blunt trauma predicted by available injury criteria is discussed. The state-of-the-art knowledge of combat helmets reviewed in this paper provides the foundation for the development of next-generation combat helmets, which are expected to protect against ballistic, blunt, and blast impacts to minimize traumatic brain injuries , while enabling wearing comfort and effective communications.

Numerical investigation of ballistic performance of SiC/TC4/UHMWPE composite armor against 7.62 mm AP projectile

With the development of weapons, monolithic armor is hard to resist these threats. Therefore, a SiC/TC4/UHMWPE laminates multi-layered composite armor against 7.62 mm armor piercing projectile is proposed in this paper. To investigate the ballistic performance of the SiC/TC4/UHMWPE laminates composite structure, a finite element model (FEM) is created in LS-DYNA. Verification FEMs are carried out on the materials of the silicon carbide (SiC) material, Ti–6Al–4V (TC4) material and ultra-high molecular weight polyethylene (UHMWPE) fiber to verify the accuracy of these materials. Furthermore, it is shown that establishing FEM of SiC/TC4/UHMWPE laminates structures can be reasonably implemented. Based on simulation results, SiC/TC4/UHMWPE laminates composite structure has a better ballistic performance than other systems using only two of the above materials. In addition, results also reveal that the SiC plate is suitable for face-sheet to wear the weight and kinetic energy of the projectile, while TC4 plate can enhance the penetration resistance of SiC plate and UHMWPE laminates backplane can maintain the integrity of the composite structure to resist higher initial velocity impact, thus providing an innovative way to improve the ballistic performance under the high-velocity impacts.

An Investigation into the Effect of Adding Carbon and Glass Fibres to UHMWPE Fibres on the Mechanical Characteristics of a Sports Prosthetic Foot

Due to their qualities and advantages, such as light weight, high rigidity, and high performance, composite materials have been used in a wide variety of industries and sectors. For example, carbon fibres are used in the construction of aircraft, while ultrahigh-molecular-weight polyethylene (UHMWPE) is used in the fabrication of medical artificial joints. In this study, the blade dimensions were estimated using side profiles from a European patent specification and the mechanical properties of numerous layers of composite materials (UHMWPE, carbon, glass fibre, and Perlon) utilized in the fabrication of sports prosthesis were investigated experimentally, theoretically, and numerically, and the results were compared, as well as the theory of failure calculated. The influence of data entered into the ANSYS programme was also investigated in the case of isotropic or orthotropic materials. The findings indicate that longitudinal young modules are experimentally and theoretically equivalent. While the material ISO or Ortho is considered and its information is entered into the ANSYS programme for the same lamina, similar results are obtained under the same boundary condition, as was demonstrated when computing the theory of failure. Additionally, it was demonstrated in this research that layering woven carbon fibre on top of layers of UHMWPE woven fabrics had a greater effect than layering woven glass fibre when fabricating the sports prosthetic foot.

Biomechanical in vitro analysis of a novel flexible implant for pubic symphysis disruption using an ultra-high molecular weight polyethylene fiber cord

BackgroundPlate osteosynthesis depicts the gold standard to surgically treat pubic symphysis disruptions. However, high rates of implant failure after plate osteosynthesis are reported, probably because of the iatrogenic arthrodesis of this fibrocartilaginous joint. Therefore, flexible implants for treatment of pubic symphysis disruptions appear to be a sensible solution. MethodsIn this biomechanical screening study, we designed and investigated a flexible implant, which consists of two plates connected with an ultra-high molecular weight polyethylene fiber cord. We mechanically tested eye splices as a possible fixation method of the cords by performing tensile load to failure tests. Afterwards, we developed a biomechanically appropriate plate design and cord routing between the plates. Finally, we biomechanically tested the flexible implant under tensile and shear loading until failure. FindingsWhen fixing a 1 mm ultra-high molecular weight polyethylene fiber cord with eye splices, a load at failure of 1570.74 N was detected under tensile loading. None of the eye splices failed but the cords itself ruptured. The load at failure of the designed cord routing in criss-cross technique and fixation within the plates amounts 4742.09 N under tensile and 2699.77 N under shear load. InterpretationWe developed a novel flexible implant for repair of pubic symphysis disruptions using ultra-high molecular weight polyethylene fiber cords connected to osteosynthesis plates. We identified eye splices as a mechanically optimal fixation method and proved that the ultra-high molecular weight polyethylene fiber cord routing and fixation of the flexible implant clearly withstands physiological forces acting on the pubic symphysis.

A parametric study on the behavior of FMLs based on UHMWPE composite under high velocity impact loading

Numerical parametric study is performed to investigate ballistic impact performance of a novel fiber metal laminate (FML) based on ultra-high molecular weight polyethylene (UHMWPE) fiber composite and aluminum 2024-T3 layers. A finite element modeling is developed and validated with experimental tests. A user-defined material subroutine based on continuum damage mechanics is used to define damage constitutive model of UHMWPE composite. High velocity impact simulations shows similar modes of failure to that observed in experiments. The effect of various parameters such as metal thickness, composite core thickness, metal volume fraction (MVF), and lay-up sequence on ballistic limit velocity, absorbed energy and specific perforation energy (SPE) of samples has been investigated. The results show that increasing the number of composite layers increases the SPE while increasing the thickness of metal layers decreases the SPE. Although, as the core thickness increases, the growth of SPE decreases. Changes in the lay-up sequence do not have much effect on ballistic velocity and absorbed energy. Whereas, the MVF is an important parameter in the high velocity impact performance of the PERALL specimens. In addition, with equal MVF, stacking sequence change has no significant effect on the ballistic limit velocity. Finally, a simple linear equation is suggested to describe the relationship between MVF and specific perforation energy.

Amidoximated UHMWPE fiber using diaminomaleonitrile as a precursor possessing excellent selectivity for uranium over vanadium in natural seawater

A novel amidoximated ultrahigh molecular weight polyethylene (UHMWPE) fiber was prepared using diaminomaleonitrile as the precursor of amidoxime group. The modified UHMWPE fibers were characterized by attenuated total reflection Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy and thermogravimetric analysis, respectively. Adsorption performances were evaluated in both simulated and natural seawater. Results showed that the uranium (U) sorption capacities were 0.41 mg/g (24 h) in simulated seawater, and 0.19 mg/g (15 d) in natural seawater, respectively. Moreover, the amidoximated UHMWPE fiber presented excellent selectivity for U over vanadium (V) in both simulated (U/V mass ratio: 20.5) and natural seawater (U/V mass ratio: 3.2).

Failure mechanism of carbon/ultra-high molecular weight polyethylene twill fiber reinforced hybrid laminates under ballistic impact

Carbon fiber reinforced plastic (CFRP) have been widely used in recent years for their high specific strength and stiffness. However, due to the high brittleness and low elongation, its application in protection engineering was limited. The introduction of other ductile fibers can ameliorate this shortcoming. In this paper, laminated construction and failure mechanism of twill carbon fiber and ultra-high molecular weight polyethylene (UHMWPE) fiber hybrid composite laminates under ballistic impact were comprehensively studied. Three different interface properties were characterized by peeling test. The simulation results were in good agreement with the ballistic impact experimental results. The sample of 4C4P with carbon fiber in the front and UHMWPE fiber in the back shows the best impact energy absorption performance,with the specific energy absorption increased by 92.22%. Based on the computed tomography (CT) scanning, delamination damage cloud images of the composite laminates were presented for the first time. The improvement of interlayer fracture toughness can enhance the impact resistance of laminates, which mainly depending on the stacking sequence and interface properties. It provided a new idea for the study of impact damage of laminated structures.